Hello Colin
A few forum members helped me find a solution to a similar problem a couple of months ago which continues to work very well for me. Assuming the hardware you’re using is not at fault, I suggest you try the same approach. This is only a work around. It may or may not work for you, but if it does, it will achieve the outcome you’re looking for i.e. transferring data to and from your eTrex H.
Begin by downloading Garmin’s “Mapsource” software from
http://www8.garmin.com/support/download_details.jsp?id=209 then proceed as follows:
To load data onto eTrex H:1. Save the files you wish to use (Waypoint/Route/Track file(s)) to your PC.
2. If these files are not in the “GPX” file format, you must first convert them (so they can be opened in Mapsource). A Google search should bring up several free software programs which will enable you to do this.
(N.B. If your files are in Google Earth’s “KML” or “KMZ” format, you can convert them very easily to the GPX format following the instructions given here:
http://www.ehow.co.uk/how_7358927_convert-kmz-file-gpx.html however this software only converts from KML/KMZ, so again, for other file types a Google search should help you to find suitable conversion software. Other forum members may also be able to point you in the right direction regarding this.)
3. Open Mapsource and connect your eTrex to the PC with the cables you have (don’t forget to load the driver software that should have been supplied with your USB to Serial Converter cable).
4. Power up the Etrex.
5. Open the GPX files in Mapsource using "File"/"Open". A graphic representation of the data should appear in the main window.
6. Click “Transfer”/”Send To Device” at the top of the Mapsource screen. A window should open allowing you to select the eTrex by clicking “Find Device”. If your eTrex H doesn’t appear in the drop down list immediately, allow 10 to 15 seconds for it to do so, and then click “Send”. The data will then be loaded onto your Satnav. If the eTrex isn’t found after the first attempt, click “Find Device” again, and allow another 15 or so seconds. I’ve found that it’s sometimes necessary to repeat this a few times before Mapsource sees the eTrex.
To save data from eTrex to PC:1. Open Mapsource and connect your eTrex to the PC with the cables you have.
2. Power up the Etrex.
3. Click “Transfer”/”Receive From Device” at the top of the screen. A window should open allowing you to select the data you wish to save to your PC (i.e. Waypoints, Routes, Tracks). Select as appropriate, and then click “Find Device”. If your eTrex H doesn’t appear in the drop down list immediately, allow 10 to 15 seconds for it to do so, and then click “Receive”. Again, more than one attempt may be necessary as described above. A graphic representation of the data should appear in the main window.
4. Click “File”/”Save as...” at the top of the screen. The “Save As” window will open allowing you to name the file, choose where you wish to save it, and for your purposes select the GPX file format from the “Save as type” drop down list.
5. Click “Save” to complete the process.
The data can then be loaded into other mapping software from the folder you saved it to, or back to your eTrex (via Mapsource as described above) whenever you wish.
Best regards
Silkylemon.